Mammoth Mountain Weather Forecast & Discusion

Monday, January 27th, 2025, @ 11 AM: Cloudy skies over the high country will clear out by Tuesday as the low heads off to the SE of Mammoth Mountain. Storm totals of 5-10 inches are reported from hill riders.

If you’re out on the hill on Tuesday, expect clear skies. Temperatures at the first chair will be in the low teens, and midday temperatures will be in the low 30s from Main Lodge down to Canyon Lodge. Over the Mid and Upper Mountain, midday temperatures will be in the mid-20s.

Winds at the 9000-foot level will be out of the North at around 10 mph, with gusts as high as 20 mph. Winds on the mid and upper mountain are expected to be out of the North at 10-20 mph, with gusts to 25-35 mph possible.

On Wednesday, expect more clear skies. Temperatures at the first chair will be in the low to mid-teens, and midday temperatures will be in the low 30s from Main Lodge down to Canyon Lodge. Over the Mid and Upper Mountain, midday temperatures will be in the upper 20s to lower 30s.

Winds at the 9000-foot level will be out of the North at around 5 mph to 10 mph. Up top winds are expected to be out of the North wind around 15-20 mph, with gusts as high as 25-35 mph.

For Thursday and Friday, skies will be clear with a 3-5 degree warmup with light winds out on the hill until about Friday afternoon, when winds could start to pick up ahead of the next system moving into the north of the Mammoth Lakes area.

The weekend outlook calls for a chance of snow showers on Saturday, cloudy skies on Sunday, and windy conditions out of the SW. If that next system sags south a bit more, there will be more snowfall.

WX Summary: This morning, a closed low is to our SE, dumping snow on the Mountains of Southern California. That low will head to the east and be replaced with some ridging for midweek. By late in the week, snow starts to move into the Northern Sierra and then slowly sags south into the weekend, with light amounts forecast for Mammoth Mountain later Saturday into Sunday.

The weekend system looks to be the first in a possible short series of systems coming in from the West. Northern California looks to be the bullseye with the tail end of the AR bands coming through Mammoth. That was the setup when all the snow came in early in the season.

The big question right now is out on days 9 – 11. The GFS has a decent AR band in the area, while the ECMWF has snow without the big AR tap. My bet is that some type of AR band comes through, but not as wet as the hyper GFS is showing right now.

Here is the low-pressure system that is currently affecting Mammoth Mountain.

Here is the low in 24 hours; as you can see, it’s a slow mover because it’s cut off from the Jet Stream.

By early Thursday, ridging is in place over the area; this should be the warmest day of the upcoming week with the lightest winds.

Jumping way out towards day 8, and you can see the next low on the ECMWF. The model is not nearly as strong with the low as the GFS below is.

ecmwf-deterministic-nepac-z500_anom-8778400

QPF from ECMWF run above.

Here is the much stronger GFS with it’s AR tap.

gfs-deterministic-nepac-z500_anom-8778400

QPF from the GFS is 4-6 inches of water, which would add up to 3-5 feet of base snow. (NO, this is not a forecast, as this storm is in the outlook period.)